Maybe the third time’s the charm for Napster. The peer-to-peer pioneer has again emerged, and this time looks to have its sights set on Apple. The company on Tuesday launched a new Web site and music store, claiming to offer six million titles in unprotected MP3 format, as many songs as Apple’s popular iTunes store but without the DRM restrictions.

Separate attempts by Napster in 2007 to partner with AOL and Circuit City fizzled.

Napster’s new site looks remarkably like the iTunes store. But upon closer inspection, the service lacks Apple’s slick and sturdy interface, and many of the listed titles are not available as MP3s. It seems that Napster might have come out of the chute a bit too early. I tried to purchase about a dozen songs, all from different artists. All but one of my purchase attempts were rejected because “the following tracks are not available for purchase.”

I’ve been using iTunes about two years now, mostly to download music for my kids. I use the Windows version, which is agonizingly slow to launch and quit. It also eats up 80 MB of hard drive space plus another 79 MB for QuickTime. And if the hard drive crashes, you’re likely to lose any songs that didn’t yet make it to the iPod or a backup disc.

On the upside, Apple’s stand-alone application maintains my kids’ music collection, automatically syncs with their iPods and offers Internet radio stations with tons of free music streams. To be fair, all those features also appear in the corresponding Napster pane, but I didn’t test any of them for this report.

When iTunes was young, Napster was king of the hill, dispensing millions of songs to billions of people without a nickel going to the RIAA. When I first heard that Apple was getting into the music business, I remember thinking that it wouldn’t be the iPod that would be revolutionize portable music—though it was a device worthy of an Apple logo. No, the real brilliance and vision was in the iTunes store—a cheap, easy legal way to obtain music for the player. The success of one would not have been possible without the other, any more than the original Macintosh could have survived without MacWrite and MacPaint.